Shareholder Report, Holdings (Details) - Fidelity Multi-Asset Index Fund |
Aug. 31, 2025 |
|---|---|
| TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 41.00% |
| TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.00% |
| TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.00% |
| TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.00% |
| TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.00% |
| TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.00% |
| TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.00% |
| AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 51.00% |
| AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.00% |
| AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.00% |
| AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.00% |